PROJECT ABSTRACT There is a major need for the widespread measurement of cardiac troponin at high sensitivity in the diagnosis of myocardial infarction. Yearly, 15 M patients present to the emergency department with symptoms of acute myocardial infarction. Rapid identification can significantly improve patient outcomes, and by ruling out those without myocardial infarction, it can save hospitals billions of dollars per year. High sensitivity cardiac troponin has become an accepted practice, but it is limited to hospitals with sophisticated centrals labs. There is no point of care version of this test which is urgently needed in pre-hospital settings and in hospitals without a central lab. We propose to develop a novel aptamer- based POC troponin assay that utilizes high-performance aptamers instead of antibodies, in a simple and robust, low cost, microfluidic device to achieve detection limit of less than 0.1 pg/ml in 20 min from blood. In phase I, we will develop a DNA aptamer pair, with ultra-high affinity and specificity against cTnI, reduced non-specific binding, resistance to heterophilic antibody interference, and increased stability and batch-to-batch consistency. We will exploit these aptamers in an electrochemical microfluidic device, with the capture aptamer immobilized on the sensor electrode, and the detection aptamer forming a DNA concatemer yielding rapid kinetics and ultra-high sensitivity, and verified the technical feasibility with clinical samples. In phase II, we will create a prototype similar to a glucose test strip, which outperforms the current standard point of care systems, validated by a retrospective clinical study in healthy and AMI patients, in comparison with commercial products. We expect to follow on with private capital or strategic investment from a partner company to proceed through clinical stage and FDA clearance via collaboration with industry partners.